Impact type piezoelectric mechanism

ABSTRACT

An impact type piezoelectric mechanism for use in igniting a gaseous fuel from a torch or a similar device. A piezoelectric element is housed in a plastic-like casing which simultaneously serves as an insulator and which is integrally connected with a U-shaped spring carrying an impact body for manually striking the piezoelectric element.

United States Patent Schweitzer [4 Apr. 11, 1972 [54] IMPACT TYPE PIEZOELE'CTRIC 3,436,l64 4/1969 Deucher ..431/25s MECHANISM 3,344,835 10/1967 Hodgson ..431/2s5 x [72] Inventor: Earl 0. Schweitzer, W1ckl 1ffe, Oh1o n" Examiner Edward G- Favors [73] Assignee: Vernitron Corporation, Bedford, Ohio Au Ed -d E, S ch [22] Filed: May 18, 1970 57 ABSTRACT [21] App]. No.: 38,233 1 An impact type piezoelectric mechanism for use in igniting a gaseous fuel from a torch or a similar device. A piezoelectric "431/ element is housed in a Plastic-like casing which simultaneously 58 Field o'isiiiii'isl i'fz''s; 310/113, Serves as an insulator and which is integrally connected with a 3 0 3 317/3 U-shaped spring carrying an impact body for manually striking the piezoelectric element. [56] References Cited 18 Claims 4 Drawing g t UNITED STATES PATENTS 3,307,053 2/1967 Furth ..43 1/258 X PATENTEDAPR 111972 v FIIG.4

FIGJ

INVENTOR. EARL O. SCHWEITZER jzw /M 1 IMPACT TYPE PIEZOELECTRIC MECHANISM The present invention relates generally to piezoelectric voltage sources and, more particularly, to a piezoelectric device in which the element is manually actuated by impact to generate electricity of igniting a gaseous fuel.

In the prior art, piezoelectric devices of the impact type are already well known. In such devices the striking mechanism is usually of a complex nature and most frequently includes a metallic compression spring for driving the piezoelectric element and also numerous components for actuating the spring and controlling the release of the potential energy embodied in the spring and for returning the loading mechanism to its normal position.

The prior art devices have been expensive to manufacture and, as a result, economic difficulties have been encountered in the marketplace. It has now been found that the piezoelectric igniter mechanism can be drastically simplified by constructing the housing, the insulation for the piezoelectric element, as well as the spring as a unitary body which is formed of plastic or similar resilient material from a single mold. This approach not only reduces the number of parts required but also facilitates the use of mass production techniques that are common in the field of plastic molding and, additionally, has the effect of appreciably reducing the weight and size of the piezoelectric device so that the same can now be used in conjunction with the air fuel mixture burning devices such as a torch. In this novel application, the igniter is simply mounted to an existing torch without hindering the operation thereof.

It is therefore the primary object of the present invention to provide a piezoelectric mechanism of the impact type which is of drastically simplified construction and therefore is free from the numerous economic disadvantages common to prior art devices.

A further object of the present invention is to provide a piezoelectrically ignited torch in which the torch incorporates the aforementioned piezoelectric igniter mechanism.

An aspect of the present invention resides in the provision of an impact type piezoelectric mechanism for use in igniting a gaseous fuel. The mechanism includes a piezoelectric element which is effective to generate electricity in response to mechanical actuation thereof. A casing encloses the axial ends of the element and a spring, which can be manually actuated, is constructed integral with the casing. An impact body is carried by the spring in a position to apply, upon actuation of the spring, an impact blow upon the piezoelectric element.

For a better understanding of the present invention, together with other and further objects thereof, reference is bad to the following description taken in connection with the accompanying drawings, and its scope will be pointed out in the appended claims.

In the drawings:

FIG. 1 is an elevational front view of a piezoelectric mechanism in accordance with the invention secured on a torch, the bottom of which is only partly shown;

FIG. 2 is a back view of the piezoelectric mechanism shown in FIG. 1 with the spring element being illustrated in several operating stages;

FIG. 3 is a perspective view of the torch nozzle outlet shown in FIG. I; and

FIG. 4 is a view similar to FIG. 2 of a slightly modified piezoelectric mechanism which, additionally, also shows the plate for securing the mechanism to the torch.

Turning now to FIGS. 1 to 3 there is shown a conventional fuel storage bottle adapted for containing a combustible gaseous fuel. The bottle 10 is further adapted to receive a conventional torch 12 which is standard and known in all respects and thus includes a tubular fuel supply line 14 and a nozzle outlet opening 16.

Secured upon the tubular fuel supply line 14 is a piezoelectric mechanism 18 of the impact type, which is to say that a striking mechanism is moved or released from a spaced position, to impact with or upon the piezoelectric element at relatively high velocity; as distinguished from devices in which a lever which is already in bearing relationship with the element squeezes the element or is effective to release a load upon the element while the loading mechanism is already in contact or bearing relationship to the piezoelectric element.

The piezoelectric mechanism 18 is secured to the tubular member 14 by means of a plate 20, such as shown in FIG. 4.

The piezoelectric mechanism 18 which, as illustrated herein, can be adapted to function as an igniter, comprises a unitary casing 22 which, in essence, serves-primarily to enclose and connect the axial ends of a piezoelectric element 24 and includes an intermediate member 26 which is provided with four laterally extending prongs 28 to maintain the piezoelectric element 24 in a predetermined position between the axially spaced portions of the casing 22.

The casing or housing 22 has a substantially rectangular configuration and integrally connected thereto is a spring-like member 30. The spring-like member is substantially U-shaped and extends from one bottom comer of the casing 22. The opposite end of the U-shaped spring-like member has a triggering handle portion 32 which extends at an angle from the ad jacent arm 34 of the U-shaped spring member 30.

The casing 22 and the spring-like member 30 are composed of either polyamide or an acital copolymer or similar highstrength plastic material which will withstand repeated manual actuation of the spring 30 and'simultaneously resist, to some degree, axial expansion of the casing 22. 1

As will be appreciated, the members 22 and 30 can be integrally molded by well known mass production techniques. Inasmuch as the aforementioned plastics exhibit electrical insulating characteristics, it is totally unnecessary to insulate the piezoelectric element 24 as was heretofore required since most, if not all, prior art devices are composed of metallic housings and other metallic actuating components.

The piezoelectric element 24 is composed of a polycrystalline ceramic material such as barium titanate, lead titanate zirconate or the like and is suitably polarized to be piezoelectrically responsive in compression and is grounded at one end, with the other end being connected through electrode wire 36 to a spark gap 38, see FIG. 3. The grounded end abuts against an anvil 40 which, in turn, is electrically connected to the tubular member 14 which terminates proximate to the spark gap 38. In order to maintain the anvil in suitable axial relationship to the axially elongated piezoelectric element 24 a small wedge 42 is interposed between the casing 22 and the anvil 40, see FIG. 2. The other end of the piezoelectric element 24 abuts against a striker pin 44 which protrudes through the casing 22 and faces an impact body or striker 46 carried in the spring-like member 30. As will be seen from FIG. 1, the striker or impact body 46 and the striker pin 44 are in mechanical juxtaposition when the spring is in a relaxed or normal state. The electrode wire 36 is electrically connected to the striker pin 44 by means of a screw 48 as illustrated in FIG. 2. The electrode wire 36, as already above mentioned, extends alongside the tubular member 14 and terminates proximate to the terminal end of the tubular member in order to establish therebetween the air gap or spark gap 38. The electrode 36 is suitably insulated to prevent a shorting of the circuit by contact with the tubular member 14 by means of insulating sleeve 50. The insulated portion of the electrode 36 is clamped to the nozzle by means of a clamp 52 which can be readily secured to and detached therefrom.

The striker body 46 and the striker pin 44 are both preferably composed of a metallic material, as is the anvil 40.

In operation, the spring 30 is actuated by manually retracting the arm 34 by means of manually pulling or pushing the triggering handle portion 32 and thereafter by suddenly releasing the handle so that the potential energy which has been stored in the elastic arm 34 by means of the retracting movement, is unloaded which causes an impact between the striker body 46 and the striker pin 44, the latter of which transmits a sudden blow upon the axial end of the piezoelectric element 24 which is effective to generate a potential which can spark across the gap 38 to ignite a fuel.

It will be appreciated that the cantilever-type construction of the spring 30 permits the device to establish a variable level of potential energy which can be adjusted to suit the needs for the particular application. In other words, in the event that a higher level of electrical energy is demanded in order to ignite a given fuel, it is solely necessary to retract the arm 34 and handle 32 to a relatively greater degree than for other relatively low level energy applications. The simplifiedspring construction is also unique in that the same is self-restoring to its normal position after actuation thereof. In most, if not all, prior art impact devices it is difficult, if not impossible, to change the load level which can be brought to bear upon the piezoelectric element.

Turning now to FIG. 4, there is shown a construction similar to the one described above in which, however, a set screw 54 is inserted through the casing 22a to engage the anvil 40 so that the pre-stressing of the piezoelectric element 24 can be more readily adjusted.

FIG. 4 also illustrates that the configuration of the springlike member 30 may take on numerous forms without, however, deviating from the basic concept of the present invention in which the particular shape may be dictated by the application for which the piezoelectric mechanism is to be employed. While tests have shown that due to the light weight of the piezoelectric mechanism the same has unique advantages when employed in conjunction with a portable torch, the invention is not limited thereto and those skilled in the art will readily appreciate that the mechanism can be employed in connection with many other uses.

While there have been described what are at present considered to be the preferred embodiments of this invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention, and it is aimed, therefore, in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What is claimed is:

1. An impact type piezoelectric mechanism for use in igniting a gaseous fuel comprising:

a piezoelectric element effective to provide a voltage spark source in response to mechanical actuation thereof;

a casing enclosing the axial ends of said element;

unitary spring means and actuator gripping means constructed integral with said casing;

an impact body fixedly carried by said actuator gripping means in a position to apply upon actuation of said spring an impact blow upon said element.

2. An impact type piezoelectric mechanism according to claim 1, wherein said spring and actuator gripping means means is responsive to manual actuation.

3. An impact type piezoelectric mechanism according to claim 2, wherein said casing is composed of electrically insulating material.

4. An impact type piezoelectric mechanism according to claim 2, wherein said casing and said spring means are composed of a plastic-like material.

5. An impact type piezoelectric mechanism according to claim 2, wherein said spring and actuator gripping means is of cantilever type construction.

6. An impact type piezoelectric mechanism according to claim 5, wherein said spring and actuator gripping means is substantially U-shaped and one arm is elastically movable to store potential energy.

7. An impact type piezoelectric mechanism according to claim 6, wherein said spring and actuator gripping means is self-restoring to its normal position after actuation thereof.

8. An impact type piezoelectric mechanism according to claim 6, wherein said spring and actuator gripping means is effective to establish a variable level of potential energy.

9. An impact type piezoelectric igniter according to claim 1, in combination with an air fuel mixture burning device;

electrode means connected to said element and providing a spark gap proximate to the flow of said fuel. An impact type piezoelectric mechanism according to claim 9, wherein said gas burning device is a portable bottle torch having a tubular nozzle provided with a fuel outlet;

mounting means detachably securing said casing to said I nozzle; and wherein the electrode spark gap is established proximate to said fuel outlet.

11. An impact type piezoelectric mechanism according to claim 10, wherein said electrode means includes an electrode detachably externally mounted on said nozzle.

12. An impact type piezoelectric mechanism according to claim 6, wherein said spring and actuator gripping means includes an integral triggering handle portion.

13. An impact type piezoelectric igniter mechanism for use in igniting a gaseous fuel, comprising:

a piezoelectric element and frame means therefor, effective to provide a voltage spark source in response to manual mechanical actuation thereof;

and integrally united actuating means and spring means, each of predominately strip-like body configuration, disposed inoperative relation to said element, composed of flexural plastic-like material, said actuating means including manual gripping means for flexing the strip-like body to store potential energy therein;

an impact body fixedly carried by said actuating means in a position to transfer at least part of said energy to said element.

14. An impact type piezoelectric igniter mechanism for use in igniting a gaseous fuel, comprising:

a piezoelectric element and frame means therefor, effective to provide a voltage spark source in response to manual mechanical actuation thereof;

integrally united actuating means and spring means, each of predominantly strip-like body configuration, disposed in operative relation to said element and composed of flexural plastic-like material, said actuating means including manual gripping means for flexing the strip-like body to store potential energy;

and an impact body fixedly carried by said actuating means in a position to transfer at least part of said energy to said element. u

15. An impact type piezoelectric mechanism for use in igniting a gaseous fuel comprising:

a piezoelectric element effective to provide a voltage spark source in response to mechanical actuation thereof;

a casing enclosing the axial ends of said element;

spring means constructed integral with said casing; and

an impact body carried by said spring means in a position to apply upon actuation of said spring an impact blow upon said element; wherein said spring means is substantially U-shaped and one arm is elastically movable to store potential energy.

16. An impact type piezoelectric mechanism according to claim 15, wherein said spring means is self-restoring to its normal position after actuation thereof.

17. An impact type piezoelectric mechanism according to claim 15, wherein said spring means is effective to establish a variable level of potential energy.

18. An impact type piezoelectric mechanism according to claim 15, wherein said spring means includes an integrally united manual gripping handle. 

1. An impact type piezoelectric mechanism for use in igniting a gaseous fuel comprising: a piezoelectric element effective to provide a voltage spark source in response to mechanical actuation thereof; a casing enclosing the axial ends of said element; unitary spring means and actuator gripping means constructed integral with said casing; an impact body fixedly carried by said actuator gripping means in a position to apply upon actuation of said spring an impact blow upon said element.
 2. An impact type piezoelectric mechanism according to claim 1, wherein said spring and actuator gripping means means is responsive to manual actuaTion.
 3. An impact type piezoelectric mechanism according to claim 2, wherein said casing is composed of electrically insulating material.
 4. An impact type piezoelectric mechanism according to claim 2, wherein said casing and said spring means are composed of a plastic-like material.
 5. An impact type piezoelectric mechanism according to claim 2, wherein said spring and actuator gripping means is of cantilever type construction.
 6. An impact type piezoelectric mechanism according to claim 5, wherein said spring and actuator gripping means is substantially U-shaped and one arm is elastically movable to store potential energy.
 7. An impact type piezoelectric mechanism according to claim 6, wherein said spring and actuator gripping means is self-restoring to its normal position after actuation thereof.
 8. An impact type piezoelectric mechanism according to claim 6, wherein said spring and actuator gripping means is effective to establish a variable level of potential energy.
 9. An impact type piezoelectric igniter according to claim 1, in combination with an air fuel mixture burning device; electrode means connected to said element and providing a spark gap proximate to the flow of said fuel.
 10. An impact type piezoelectric mechanism according to claim 9, wherein said gas burning device is a portable bottle torch having a tubular nozzle provided with a fuel outlet; mounting means detachably securing said casing to said nozzle; and wherein the electrode spark gap is established proximate to said fuel outlet.
 11. An impact type piezoelectric mechanism according to claim 10, wherein said electrode means includes an electrode detachably externally mounted on said nozzle.
 12. An impact type piezoelectric mechanism according to claim 6, wherein said spring and actuator gripping means includes an integral triggering handle portion.
 13. An impact type piezoelectric igniter mechanism for use in igniting a gaseous fuel, comprising: a piezoelectric element and frame means therefor, effective to provide a voltage spark source in response to manual mechanical actuation thereof; and integrally united actuating means and spring means, each of predominately strip-like body configuration, disposed in operative relation to said element, composed of flexural plastic-like material, said actuating means including manual gripping means for flexing the strip-like body to store potential energy therein; an impact body fixedly carried by said actuating means in a position to transfer at least part of said energy to said element.
 14. An impact type piezoelectric igniter mechanism for use in igniting a gaseous fuel, comprising: a piezoelectric element and frame means therefor, effective to provide a voltage spark source in response to manual mechanical actuation thereof; integrally united actuating means and spring means, each of predominantly strip-like body configuration, disposed in operative relation to said element and composed of flexural plastic-like material, said actuating means including manual gripping means for flexing the strip-like body to store potential energy; and an impact body fixedly carried by said actuating means in a position to transfer at least part of said energy to said element.
 15. An impact type piezoelectric mechanism for use in igniting a gaseous fuel comprising: a piezoelectric element effective to provide a voltage spark source in response to mechanical actuation thereof; a casing enclosing the axial ends of said element; spring means constructed integral with said casing; and an impact body carried by said spring means in a position to apply upon actuation of said spring an impact blow upon said element; wherein said spring means is substantially U-shaped and one arm is elastically movable to store potential energy.
 16. An impact type piezoelectric mechanism according to claim 15, wherein said spring means is self-restoring to its normal position after aCtuation thereof.
 17. An impact type piezoelectric mechanism according to claim 15, wherein said spring means is effective to establish a variable level of potential energy.
 18. An impact type piezoelectric mechanism according to claim 15, wherein said spring means includes an integrally united manual gripping handle. 